The present invention concerns a fluid treating device, containing a number of vessels through which the fluid is led, at least two feed pipes and at least two discharge pipes and a distributing device to control the flow of fluid from the feed pipes through the vessels and to the discharge pipes.
The invention in particular concerns such a device for bringing a liquid into contact with a solid matter situated in the vessels.
Such devices are used among others for treating a liquid in ion exchangers. The vessels are filled with ion-exchange resin. Via the distributing valve, the liquid to be treated is led through a number of said vessels, whereas a second fluid is led through other vessels for the regeneration of the ion-exchange resin or for other purposes.
After the liquid has been treated in a chamber for some time, the resin in this chamber needs to be regenerated, which implies that the position of the distributing device must be altered so as to cut off the passage of the above-mentioned liquid to the chamber and to send liquid for the regeneration through this chamber instead.
A device of the above-described type is for example disclosed in U.S. Pat. No. 5,069,883. The vessels are erected on a rotating table.
This distributing device consists of a cylinder which rotates along with the table and which can rotate with its lower part in a stationary cylinder.
The vessels are connected to openings in the wall of the rotating cylinder via pipes. The feed and discharge pipes are connected to openings in the wall of the stationary cylinder, whereby by bringing these openings right opposite to the openings in the wall of the rotating cylinder, the connections between the pipes are made.
The rotating cylinder hereby has to be positioned very precisely to make the openings fit exactly, which may cause problems. Moreover, all the vessels need to be rotated, which implies a complicated and relatively expensive construction.
In NL-C-1.008.704 is also described such a device.
In this embodiment as well, the vessels are erected on a table which is continuously rotated. The distributing device consists of a rotating valve.
This rotating valve contains a first disc which rotates coaxially along with the table, which is provided with openings which are connected to the inlets and the outlets of the vessels via pipes and which is connected to a second disc in a sealing manner, which is also provided with openings and which can rotate back and forth at a restricted angle.
The feed and discharge pipes which are flexible are connected to the openings in the second disc. These pipes rotate along with the first disc at a restricted angle, while being connected to certain openings in the first disc, and then return quickly to rotate along with the first disc again, but now connected to other openings in the first disc, i.e. with other vessels.
It is clear that this device, which is known as well, has a complicated construction. The rotating valve has two separate moving parts, and separate drives are required for the table and the second disc of the rotating valve. Moreover, the feed and discharge pipes have to be expensive flexible pipes.
U.S. Pat. No. 2,706,532 discloses a fluid treating apparatus wherein the distributing valve comprises a disc mounted inside a cylindrical housing forming a closed chamber for rotation about the longitudinal axis thereof. The disc comprises in its top and bottom sides a number of concentric annular-trough shaped conduits and a number of concentric arc-shaped and trough-shaped conduits.
Inlet conduits are connected to the upper part of the housing and end each in an annular-trough shaped conduit in the top side of the disc. Outlet conduits are connected to the lower part of the housing and end each in an annular-trough shaped conduit in the lower side of the disc.
The arc-shaped conduits in the bottom side are in communication with a group of openings in the lower part of the housing, which openings are connected by connecting pipes to one end of vessels, while the arc-shaped conduits in the top side of the disc are in communication with a group of openings which are connected by means of connecting pipes to the other end of vessels.
Connecting channels in the disc form each a passageway between one of the arc-shaped conduits on one side of the disc and one of the annular-trough shaped conduits on the opposite side of the disc.
This treatment device requires a relatively complicated distribution device. Fluid from the outlets of a number of vessels is collected as the connecting pipes connected to these outlets are connected to a top of bottom portion of the housing and end in a same arc-shaped conduit in the disc. The distributing device uses thus only one dimension, this is the vertical dimension, from top to bottom or vice versa, to make the process connections, which limits the possibilities. The vessels are divided in groups and the flow is changed by the distribution device per group, which also limits the possibilities.
The invention aims a fluid treating device which does not have the above-mentioned disadvantages and which has a simple construction.
This aim is reached according to the invention in a fluid treating device, containing a number of vessels through which the fluid is led; at least two feed pipes and at least two discharge pipes; and a distributing device to control the flow of fluid from the feed pipes through the vessels and to the discharge pipes, whereby the distributing device contains at least one revolving disc having an axis of rotation in its centre, rotatably mounted in a stationary housing which is in sealing engagement with the outside of the revolving disc; and rotating means for rotating the revolving disc; whereby said housing comprises two end walls and a side wall having an inner surface concentric with the rotating axis, and the feed pipes and the discharge pipes are connected to one end wall of the housing and open onto the revolving disc in said housing, and whereby the stationary vessels are also connected to said housing via connecting pipes and open onto the revolving disc, and whereby the disc is provided by passageways, the feed pipes and the discharge pipes each opening into these passageways via a ring-shaped duct extending in a closed circle around the axis of rotation, so that for a number of positions of the disc, each feed pipe and discharge pipe can be put into connection with at least one vessel, which treatment device is characterised in that the passageways inside the disc open onto the outer surface of the disc extending around the rotation axis while the connecting pipes from or to the stationary vessels are connected to the side wall of the housing and open onto said outer surface of the disc, so that in said positions of the disc, one connecting pipe from a vessel is in fluid connection with one passageway, and this passageway is, either, together with others, in fluid connection with a feed or discharge pipe through the intermediary of a ring-shaped duct, or in fluid connection with another passageway.
The ring-shaped ducts can be situated on the outside of the revolving disc or on the inside in the housing, but each feed pipe or discharge pipe is preferably connected to both a ring-shaped duct on the inside of the housing and a ring-shaped duct situated opposite to it on the outside of the revolving disc, whereby one or several passageways are connected to the latter ring-shaped duct.
The distributing device may comprise a single disc inside the housing, in which case the passageways assure each, for the above positions of the disc, fluid connection between one connecting pipe and a ring-shaped duct to which is connected a feed pipe or a discharge pipe, or between one connecting pipe and another one.
In another embodiment the distributing device comprises two or more coaxial adjacent discs inside the housing and different rotating means for each disc so that they can rotate at a different rotation speed, whereby connection pipes connected to a number of the vessels open onto one of the discs, while connection pipes connected to other vessels open onto another disc, additional ring-shaped ducts being present in the side adjacent to the other disc of one or both of the adjacent discs, a number of additional passageways in each disc being connected to the last mentioned additional ring-shaped ducts, such that, for the a number of positions of the discs, one connection pipe connected the inlet of a vessel opens on one disc into a passageway in connection with a ring-shaped duct to which is connected a feed pipe, while the connecting pipe connected to the outlet of said vessel opens into one of said additional passageways in the last mentioned disc which is in connection with one of said additional ring-shaped ducts and the connecting pipe connected to the inlet of another vessel opens onto the other disc into one of the additional passageways in this disc which is in connection with the last mentioned additional ring-shaped duct, while the connecting pipe connected to the outlet of said another vessel (1-AN) opens on the last mentioned disc, into a passageway connected to a ring-shaped duct to which a discharge pipe is connected.
In fact the vessels are divided in as much groups as there are discs, for instance in cation cells and anion cells and fluid flows from cells of the first group to cells of another group and flows with a different speed through the vessels of different groups.